package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.Collections;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;
    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }
    @Override
    public Result seckillVocher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        long orderId = redisIdWorker.nextId("order");
        // 1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(), String.valueOf(orderId)
        );
        int r = result.intValue();
        // 2.判断结果是否为0
        if (r != 0) {
            // 2.1.不为0 ，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //TODO 保存阻塞队列

        // 3.返回订单id
        return Result.ok(orderId);
    }
//    public Result seckillVocher(Long voucherId) {
//        // 1.查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        // 2.判断秒杀是否开始
//        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
//            // 尚未开始
//            return Result.fail("秒杀尚未开始！");
//        }
//        // 3.判断秒杀是否已经结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            // 尚未开始
//            return Result.fail("秒杀已经结束！");
//        }
//        // 4.判断库存是否充足
//        if (voucher.getStock() < 1) {
//            // 库存不足
//            return Result.fail("库存不足！");
//        }
//        Long userId =UserHolder.getUser().getId();
//        //创建锁对象
////        SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        //判断是否获取锁成功
//        if (!isLock) {
//            // 获取锁失败，直接返回失败或者重试
//            return Result.fail("不允许重复下单！");
//        }
//
//        try {
//            //获取代理对象(事务)
//            IVoucherOrderService  proxy = (IVoucherOrderService)AopContext.currentProxy();
//            return proxy.creatVoucherOrder(voucherId);
//        } finally {
//            //释放锁
//            lock.unlock();
//        }
//
//    }

    @Transactional
    public Result creatVoucherOrder(Long voucherId) {
        //5.一人下一单
        Long userId =UserHolder.getUser().getId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
        if(count>0){
            //用户已经购买过
            return Result.fail("用户已经购买过一次！");
        }

        // 5.扣减库存
        boolean success = seckillVoucherService.update()
                . setSql("stock = stock - 1")
                .eq("voucher_id", voucherId).gt("stock", 0)
                .update();
        if(!success){
            //扣减失败
            return Result.fail("库存不足！");
        }
        //6.创建订单
        VoucherOrder voucherOrder = new VoucherOrder();
        // 6.1.订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);
        // 6.2.用户id

        voucherOrder.setUserId(userId);
        // 6.3.代金券id
        voucherOrder.setVoucherId(voucherId);
        save(voucherOrder);
        return Result.ok(orderId);
    }
}
